202 citations · 1.3k across the 78 of their papers we have counts for
9 papers · 1 filter
QCD beyond diagrams
Michael Creutz
QCD, the theory of the strong interactions, involves quarks interacting with non-Abelian gluon fields. This theory has many features that are difficult to impossible to see in conv…
Quark masses in two-flavor QCD
Michael Creutz
Considered as a function of the quark mases, two-flavor QCD depends on three parameters, including one that is CP violating. As the masses vary to unphysical values, regions of bot…
Quark mass dependence of two-flavor QCD
Michael Creutz
I explore the rich phase diagram of two-flavor QCD as a function of the quark masses. The theory involves three parameters, including one that is CP violating. As the masses vary,…
Anomalies and discrete chiral symmetries
Michael Creutz
The quantum anomaly that breaks the U(1) axial symmetry of massless multi-flavored QCD leaves behind a discrete flavor-singlet chiral invariance. With massive quarks, this residual…
Anomalies and chiral symmetry in QCD
Michael Creutz
I review some aspects of the interplay between anomalies and chiral symmetry. The quantum anomaly that breaks the U(1) axial symmetry of massless QCD leaves behind a flavor-singlet…
The 't Hooft vertex revisited
Michael Creutz
In 1976 't Hooft introduced an elegant approach towards understanding the physical consequences of the topological structures that appear in non-Abelian gauge theories. These effec…
Ambiguities in the up quark mass
Michael Creutz
It has long been known that no physical singularity is encountered as up quark mass is adjusted from small positive to negative values as long as all other quarks remain massive. T…
Quark masses, chiral symmetry, and the U(1) anomaly
Michael Creutz
I discuss the mass parameters appearing in the gauge theory of the strong interactions, concentrating on the two flavor case. I show how the effect of the CP violating parameter $θ…
Species Doubling and Chiral Lagrangians
Michael Creutz, Michel Tytgat
Coupling gauge fields to the chiral currents from an effective Lagrangian for pseudoscalar mesons naturally gives rise to a species doubling phenomenon similar to that seen with fe…